This book constitutes the refereed proceedings of the 6th International Conference on Formal Concept Analysis, ICFCA 2008, held in Montreal, Canada, in February 2008. The 23 revised full papers presented were carefully reviewed and selected from numerous submissions for inclusion in the book. The papers comprise state of the art research and present new results in Formal Concept Analysis and related fields. These results range from theoretical novelties to advances in FCA-related algorithmic issues, as well as application domains of FCA such as data visualization, information retrieval, machine learning, data analysis and knowledge management.